1. Field of the Invention
The invention refers to a light-emitting diode (LED), and particularly to a packaging structure of an LED for improving fabricating yield and avoiding short circuit of adjacent LED packaging structures due to contact of their conductive elements.
2. Description of the Prior Art
Reference is made to FIG. 1, which is a prior art packaging structure of an LED as disclosed in U.S. Pat. No. Re. 36614, comprising a substrate 10a, a light-emitting chip 20a, a conducting wire 30a and a protective unit 40a (which is hereby incorporated by reference). The substrate 10a further comprises two conductor materials 50a respectively disposed on the upper surface of the substrate 10a to form a conductive pad 51a and a conductive strip 52a on the substrate 10a, respectively, and further extending respectively along the opposite half-circle side walls of the substrate 10a to the lower surface the substrate 10a to form an electrode pad 53a thereon. One side of the light-emitting chip 20a is electrically connected and secured to one of the conductive pad 51a, and the conducting wire 30a is used at both ends thereof to connected electrically and respectively to the other conductive strip 52a and the other side of the light-emitting chip 20a. Using the protection unit 40a, the light-emitting chip 20a, the conductive pad 51a, the conductive strip 52a and the conducting wire 30a are encapsulated on the upper surface of the substrate 10a. 
In this case, the packaging structures of the LED are mass-manufactured by forming a plurality of LED packaging structures on a large-area substrate. To do this, a plurality of circle holes are formed on the large substrate, then the conductive pads, conductive strips and electrode pads are disposed on the upper and lower surfaces and the circle hole walls of the substrate by electroplating and etching; further, the light-emitting chips are disposed and electrically connected thereon, and then encapsulated by the protection unit on the substrate. Consequently, a plurality of interconnected LED packaging structures are formed. Finally the substrate is sliced along the direction of the aligned holes to separate the substrate into individual LED packaging structures with two opposite half-circle side walls. However, since the large-area substrate may be obliquely cut during the slicing process, this results in irregular half-circle side walls, thereby decreasing product yield.
Moreover, when a plurality of LED packaging structures are aligned in a matrix arrangement for use of display device, and two adjacent packaging structures are positioned close and thus may contact each other (as shown in FIG. 2), the half-circle side walls and the electrode pads of the adjacent LED packaging structures may be positioned close to and be in contact with each other, thereby resulting in a short-circuit. Therefore, two LED packaging structures need separated by a certain interval or a isolation element is disposed between two adjacent LED packaging structures, so as to avoid short-circuits of adjacent LED packaging structures. As a result, assembly and fabrication take longer and are more expensive, thereby leading to the degradation of the competitive power of the products.
Accordingly, this invention is provided to improve the above disadvantages with a reasonable design.